40,374 research outputs found
Bayesian analysis of CCDM Models
Creation of Cold Dark Matter (CCDM), in the context of Einstein Field
Equations, leads to negative creation pressure, which can be used to explain
the accelerated expansion of the Universe. In this work we tested six different
spatially flat models for matter creation using statistical tools, at light of
SN Ia data: Akaike Information Criterion (AIC), Bayesian Information Criterion
(BIC) and Bayesian Evidence (BE). These approaches allow to compare models
considering goodness of fit and number of free parameters, penalizing excess of
complexity. We find that JO model is slightly favoured over LJO/CDM
model, however, neither of these, nor model can be
discarded from the current analysis. Three other scenarios are discarded either
from poor fitting, either from excess of free parameters.Comment: 16 pages, 6 figures, 6 tables. Corrected some text and language in
new versio
Nematic liquid crystal dynamics under applied electric fields
In this paper we investigate the dynamics of liquid crystal textures in a
two-dimensional nematic under applied electric fields, using numerical
simulations performed using a publicly available LIquid CRystal Algorithm
(LICRA) developed by the authors. We consider both positive and negative
dielectric anisotropies and two different possibilities for the orientation of
the electric field (parallel and perpendicular to the two-dimensional lattice).
We determine the effect of an applied electric field pulse on the evolution of
the characteristic length scale and other properties of the liquid crystal
texture network. In particular, we show that different types of defects are
produced after the electric field is switched on, depending on the orientation
of the electric field and the sign of the dielectric anisotropy.Comment: 7 pages, 12 figure
Suppression of two-bounce windows in kink-antikink collisions
We consider a class of topological defects in -dimensions with a
deformed kink structure whose stability analysis leads to a
Schr\"odinger-like equation with a zero-mode and at least one vibrational
(shape) mode. We are interested in the dynamics of kink-antikink collisions,
focusing on the structure of two-bounce windows. For small deformation and for
one or two vibrational modes, the observed two-bounce windows are explained by
the standard mechanism of a resonant effect between the first vibrational and
the translational modes. With the increasing of the deformation, the effect of
the appearance of more than one vibrational mode is the gradual disappearance
of the initial two-bounce windows. The total suppression of two-bounce windows
even with the presence of a vibrational mode offers a counterexample from what
expected from the standard mechanism. For even larger deformation, some
two-bounce windows reappear, but with a non-standard structure.Comment: 13 pages, 6 figure
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